Extensible and retractable telescoping mast.



A. SIEWERT. BXTENSIBLE AND RBTRAGTABL'B TBLEscoPING MAST.

APPLICATION FILED 00T. 14, 1910.

Patented Apr. 11, 1911.

A. SIEWERT. EXTENSIBLE AND RBTRACTABLB TELBSGOPING MAST.

APPLICATION FILED 00T. 14. 1810.

PatenteaApr. 11, 1911.

I ALEXANDER SIEWERT, F BERLIN, GERMANY. 4

EXTENSIBLE AND RETRAGTABLE TELESOOPING'MAST,

Specification of Letters Patent. Patented Apr. 11, 1911.

Application led October 14, 1910. Serial No. 587,110.

To all 'whom 'it may concern.'

Be it known that I, ALEXANDER SIEwER'r,

specification.

The present invention relates to an improvement and development of the extensible and retractable masts of the kind set forth in my pending application for Letters Patent Serial No. 492,078.

The improvement relates especially to the construction illustrated in Figures 7 and 8 of the prior application in which the diameter of the mast is diminished stepwise from below upward.

The present invention comprises the improvemeut that the binding pieces are constructed as sleeves surrounding the outline of the mast and similarly stepwise decreasing in diameter.

Referring to the accompanying drawings in which these constructions of they invention are illustra-tedin sixteen figures in lon 'tu` dinal and transverse section respective y as follows: Fig. 1 shows a longitudinal section of oneconst-ruction. Fig. 2 the corresponding transverse section. Fig. 3 shows a 1ongitudinal section of another construction. Fig.- 4 the corresponding transverse section. Fig. 5 shows a longitudinal section on the line A-A of Fig. 7. Fi 6 is a longitudinal section on the line D of Fig. 8. Fig. 7 a transverse section of Fig. 5. Flg. 8 a transverse section of Fig. 6. Fig. 9 a longitudinal section of another construction. Fig. 10 the corresponding transverse section. Fig. 11 a longitudinal sect-ion of another construction on the line C--C of Fig. 12. Fig. 12 the corresponding transverse section. Fig. 13 is a longitudinal section on the line D-D of Fig. 14. Fig. 14 is the corresponding transverse section. Fig. 15 is a longitudinal section of another construction. Fig. 16 the corresponding transverse section.-

In the first constructions illustrated inl Figs. 1 to 4, the extensible mast possesses a cruciform shape and is constructed of a stepwise diminishing central band 1 and the two likewise diminishing transverse bands 2. The bending out of shape and folding are prevented by the sleeve-shaped envelops '3, which possess either a circular section as s hown in Figs. 1 and 2, or a quadratic section as shown in Figs. 3 and 4,'and which rest at their lower ends upon the footings of the bands. These envelops 3 diminish stepwise in diameter so that they can be inclosed one within another. In order to prevent a displacement of the transverse bands 2 with regard to the middle band 1 there is provlded upon the latter a number of projections 4.

The third constructional example is illustrated in Figs. 5 to 8 as 'already stated. In this construction the retractable mast possesses a rectangular cross section and the two wide bands 5 are likewise stepwise diminished. while the two narrow bands 6 extend from top to bottom of the same width and as illustrated in Fig. 6 are inclined inward toward each other upward.

In the fourth constructional example illustrated in Figs. 9 and 10, the mast is composed of two parallel strips 7 which are firstly held in shape by means of the sleeves 3 surrounding them, and secondly by means of a zigzag band 8 placed between them.

The fifth constructional example is illustrated in Figs. 11 to 14. In these constructions the mast has a rectangular cross section and the stepwise diminishing strips have their edges formed as square teeth so that the edges of two strips placed at an angle can engage with lone another.

Figs. 15 and 16 illustrate a construction corresponding to Figs. 13 and 14, which how'- ever, instead of having a quadratic section, possesses a hexagonal section. The -sleeves 3 act in the same manner as the cross bands referred to in my previous application to prevent the bending of the strips out o shape or the folding thereof; 'they consequently form an effective reinforcement of the` rigid steel strip core and at "the same time constitute a defense for it against the action of the weather or mechanical injuries. Moreover the core of the mast formed of the steel strips serves to raise the sleeves and to strengthen them against side strains. Consequently there exists in the above described combination of stepwise varying sleeves and the steel strip core, a mutual support which secures a great rigidity for the construction.

What- I claim is:

1. An extensible and retractable mast composed of a plurality of flexible metal strips detachably assembled around a commonlongitudinal axis at an angle one to another land adapted to be coiled for retracting, in combination with encircling sleeves of progressively diminishing diameter, each sleeve adapted to slide Wlthin the next larger sleeve.

2. An extensible and retractable mast composed of a plurality ofy flexible metal strips diminishing stepwise in Width, detachably assembled around a common longitudinal axis at an angle one to another and adapted to be coiled for retracting, incombination with encircling sleeves of progressively diminishing diameter, each sleeve adapted to slide Within the next larger sleeve.

In testimony whereof I have signed my 15 name to this specification in the presence of two subscribing Witnesses.

WOLDEMAR HAUPT, HENRY HASPER. 

